The present invention relates to electronics assemblies, and is primarily concerned with racked assemblies. Many such assemblies will be located in racks for housing in for example nineteen inch cabinets, or other size cabinets such as twenty three inch or metric cabinets. The assemblies may for instance be employed as servers for a number of systems, for example in local area networks (LANs), wide area networks (WANs), telecommunications systems or other operations such as database management or as internet servers.
Such an assembly will typically comprise an enclosure, for example in the form of a supporting chassis that houses a motherboard or backplane and a number of daughterboards or module cards that extend in planes generally perpendicular to the plane of the motherboard. Other components may be included, such as power supply units, hard disc drives, tape drives, ROM drives etc., with the result that the space available for provision of all the services in the enclosure is severely limited, and no internal space of the enclosure can be wasted.
One form of computer, called xe2x80x9cRAS computersxe2x80x9d that is to say, computers that need to provide a high degree of reliability, availability and serviceability need to maximise the length of time during which the computer is operational. The computer may need to withstand a considerable degree of vibration, whether to particular office conditions or because of seismic activity, and so needs to exhibit a high degree of ruggedness. Furthermore, any periods during which the computer is down for example due to repair or maintenance should be minimised, which requires reducing the time taken to remove and reinstall any components of the system.
According to one aspect of invention, there is provided a spring retaining mechanism for an enclosure in the form of a leaf spring to retain the component(s) in the enclosure, but which is not permitted to move sufficiently to lose its elasticity over time.
According to another aspect of the invention, there is provided an enclosure for an electronics assembly, which comprises
(i) a housing having a recess; and
(ii) a module for holding one or more components of the assembly, the module being insertable into the recess by sliding, and removable therefrom by sliding in a direction opposite to the direction of insertion; and
(iii) a spring retaining element located in one of the housing and the module, the element being in the form of a resiliently deformable arm that engages the other of the housing and the module when the module is inserted into position within the recess in order to prevent removal of the module from the recess,
wherein the arm can be manually bent to release the module from the recess, but the housing or the module allows a degree of movement of the retaining element during release of the module that is insufficient to allow the arm to bend beyond its elastic limit.
The invention has the advantage that the electronics enclosure allows speedy removal and replacement of modular components thereof, but which will hold the components securely therein and will take up a minimum of space.
The module need not be a complete working unit of the electronics assembly, but may instead be in the form of a container that can house one or more other components thereof. The other components may themselves be modular, and may be insertable into the module by sliding, and be retained within the module by means of a retaining element as described above. In such a case, the module may be regarded as an enclosure that contains further modules.
The arm may have an intermediate shoulder that engages the module or the housing when the module is in position in the recess in order to retain the module within the recess. In such a case, the shoulder of the retaining element may engage the module or the housing at an intermediate point on the module (in the direction of insertion thereof) and the arm may extend further, for a sufficient distance that it extends beyond the end of the module in order to allow manipulation of the retaining element by the service engineer.
According to yet another aspect, the invention provides an enclosure for an electronics assembly, which comprises a housing having a recess, that can receive a module by sliding the module therein, the housing having a spring retaining element in the form of a resiliently deformable arm for preventing removal of the module from the recess, wherein the arm can be manually bent to release the module from the recess, but the housing allows a degree of movement of the retaining element during release of the module that is insufficient to allow the arm to bend beyond its elastic limit.
According to a further aspect, the invention provides a module for holding one or more components of an electronics assembly, the module being insertable into a recess in a housing by sliding, the module having a spring retaining element in the form of a resiliently deformable arm for preventing removal of the module from the recess, wherein the arm can be manually bent to release the module from the recess, but the module allows a degree of movement of the retaining element during release of the module that is insufficient to allow the arm to bend beyond its elastic limit.